Exercise 2.7

Question 1

Find:

(i) $0.4 \div 2$

Sol :

$0.4 \div 2$ $=\dfrac{4}{10} \div 2$

(ii) $0.35 \div 5$

Sol :

$0.35 \div 5$ $=\dfrac{35}{100} \div 5$ $=\dfrac{35}{100} \times \dfrac{1}{5}$ $=\dfrac{7}{100}$ = 0.07

(iii) $2.48 \div 4$

Sol :

$2.48 \div 4$ $=\dfrac{248}{100} \div 4$ $=\dfrac{248}{100} \times \dfrac{1}{4}$ $=\dfrac{62}{100}$ = 0.62

(iv) $65.4 \div 6$

Sol :

$65.4 \div 6$ $=\dfrac{654}{10} \div 6$ $\dfrac{654}{10} \times \dfrac{1}{6}$ $=\dfrac{109}{10}$ = 10.9

(v) $651.2 \div 4$

Sol :

$651.2 \div 4$ $=\dfrac{6512}{10} \div 4$ $=\dfrac{6512}{10} \times \dfrac{1}{4}$ $=\dfrac{1628}{10}$ = 162.8

(vi) $14.49 \div 7$

Sol :

$14.49 \div 7$ $=\dfrac{1449}{100} \div 7$ $=\dfrac{1449}{100} \times \dfrac{1}{7}$ $=\dfrac{207}{100}$ = 2.07

(vii) $3.96 \div 4$

Sol :

$3.96 \div 4$ $=\dfrac{396}{100} \div 4$ $=\dfrac{396}{100} \times \dfrac{1}{4}$ $=\dfrac{99}{100}$ = 0.99

(viii) $0.80 \div 5$

Sol :

$0.80 \div 5$ $=\dfrac{80}{100} \div 5$ $=\dfrac{80}{100} \times \dfrac{1}{5}$ $=\dfrac{16}{100}$ =0.16

Question 2

Find:

(i) $4.8 \div 10$

Sol : 0.48

(ii) $52.5 \div 10$

Sol : 5.25

(iii) $0.7 \div 10$

Sol : 0.07

(iv) $33.1 \div 10$

Sol : 3.31

(v) $272.23 \div 10$

Sol : 27.223

(vi) $0.56 \div 10$

Sol : 0.056

(vii) $397\div 10$

Sol : 0.397

Note : We know that when a decimal number is divided by a multiple of 10 only (i.e., 10, 100, 1000, etc.), the decimal point will be shifted to the left by as many places as there are zeroes. Since here we are dividing by 10, the decimal will shift to the left by 1 place.

Question 3

Find:
(i) $2.7 \div 100$

Sol : 0.027

(ii) $0.3 \div 100$

Sol : 0.003

(iii) $0.78 \div 100$

Sol : 0.0078

(iv) $432.6 \div 100$

Sol : 4.326

(v) $23.6 \div 100$

Sol : 0.236

(vi) $98.53 \div 100$

Sol : 0.9853

Notes : We know that when a decimal number is divided by a multiple of 10 only (i.e., 10, 100, 1000, etc.), the decimal point will be shifted to the left by as many places as there are zeroes. Since here we are dividing by 100, the decimal will shift to the left by 2 places.

Question 4

Find:
(i) $7.9 \div 1000$